Naming and coding style convention, new linter tool. (#945)

* Makefile, Scripts: new linter
* About: remove ID from IC
* Firmware: remove double define for DIVC/DIVR
* Scripts: check folder names too. Docker: replace syntax check with make lint.
* Reformat Sources and Migrate to new file naming convention
* Docker: symlink clang-format-12 to clang-format
* Add coding style guide

applications/power/power_cli.c

@@ -2,7 +2,7 @@
 
 #include <power/power_service/power.h>
 #include <cli/cli.h>
-#include <furi-hal.h>
+#include <furi_hal.h>
 
 void power_cli_poweroff(Cli* cli, string_t args, void* context) {
     Power* power = furi_record_open("power");